> On Thu, Mar 26, 2009 at 06:25:19PM -0700, Andrew Morton wrote:> > The JBD journal is a massive designed-in contention point. It's why> > for several years I've been telling anyone who will listen that we need> > a new fs. Hopefully our response to all these problems will soon be> > "did you try btrfs?".> > Oh I look forward to the day when it will be safe to convert my mythtv> box from ext3 to btrfs. Current kernels just have too much IO latency> with ext3 it seems. Older kernels were more responsive, but probably> had other places they were less efficient.

Back in 2002ish I did a *lot* of work on IO latency, reads-vs-writes,etc, etc (but not fsync - for practical purposes it's unfixable onext3-ordered)

Performance was pretty good. From some of the descriptions I'm seeingget tossed around lately, I suspect that it has regressed.

It would be useful/interesting if people were to rerun some of thesetests with `echo anticipatory > /sys/block/sda/queue/scheduler'.Or with linux-2.5.60 :(